31221231000 has 128 divisors (see below), whose sum is σ = 103140423360. Its totient is φ = 7835904000.

The previous prime is 31221230933. The next prime is 31221231001. The reversal of 31221231000 is 13212213.

It is a super-2 number, since 2×31221231000² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221231001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 255091 + ... + 357090.

Almost surely, 2^31221231000 is an apocalyptic number.

31221231000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31221231000 is an abundant number, since it is smaller than the sum of its proper divisors (71919192360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31221231000 is a wasteful number, since it uses less digits than its factorization.

31221231000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612222 (or 612208 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31221231000 its reverse (13212213), we get a palindrome (31234443213).

The spelling of 31221231000 in words is "thirty-one billion, two hundred twenty-one million, two hundred thirty-one thousand".